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@@ -1,126 +1,125 b'' | |||
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1 | 1 | """SelectionWidget classes. |
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2 | 2 | |
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3 | 3 | Represents an enumeration using a widget. |
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4 | 4 | """ |
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5 | 5 | #----------------------------------------------------------------------------- |
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6 | 6 | # Copyright (c) 2013, the IPython Development Team. |
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7 | 7 | # |
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8 | 8 | # Distributed under the terms of the Modified BSD License. |
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9 | 9 | # |
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10 | 10 | # The full license is in the file COPYING.txt, distributed with this software. |
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11 | 11 | #----------------------------------------------------------------------------- |
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12 | 12 | |
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13 | 13 | #----------------------------------------------------------------------------- |
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14 | 14 | # Imports |
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15 | 15 | #----------------------------------------------------------------------------- |
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16 | 16 | |
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17 | 17 | from collections import OrderedDict |
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18 | 18 | from threading import Lock |
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19 | 19 | |
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20 | 20 | from .widget import DOMWidget |
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21 | 21 | from IPython.utils.traitlets import Unicode, List, Bool, Any, Dict, TraitError |
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22 | 22 | from IPython.utils.py3compat import unicode_type |
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23 | 23 | |
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24 | 24 | #----------------------------------------------------------------------------- |
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25 | 25 | # SelectionWidget |
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26 | 26 | #----------------------------------------------------------------------------- |
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27 | 27 | class _SelectionWidget(DOMWidget): |
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28 | 28 | """Base class for Selection widgets |
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29 | 29 | |
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30 | 30 | ``values`` can be specified as a list or dict. If given as a list, |
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31 | 31 | it will be transformed to a dict of the form ``{str(value):value}``. |
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32 | 32 | """ |
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33 | 33 | |
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34 | 34 | value = Any(help="Selected value") |
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35 | 35 | values = Dict(help="""Dictionary of {name: value} the user can select. |
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36 | 36 | |
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37 | 37 | The keys of this dictionary are the strings that will be displayed in the UI, |
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38 | 38 | representing the actual Python choices. |
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39 | 39 | |
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40 | 40 | The keys of this dictionary are also available as value_names. |
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41 | 41 | """) |
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42 | 42 | value_name = Unicode(help="The name of the selected value", sync=True) |
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43 | 43 | value_names = List(Unicode, help="""Read-only list of names for each value. |
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44 | 44 | |
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45 | 45 | If values is specified as a list, this is the string representation of each element. |
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46 | 46 | Otherwise, it is the keys of the values dictionary. |
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47 | 47 | |
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48 | 48 | These strings are used to display the choices in the front-end.""", sync=True) |
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49 | 49 | disabled = Bool(False, help="Enable or disable user changes", sync=True) |
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50 | 50 | description = Unicode(help="Description of the value this widget represents", sync=True) |
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51 | 51 | |
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52 | 52 | |
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53 | 53 | def __init__(self, *args, **kwargs): |
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54 | 54 | self.value_lock = Lock() |
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55 | 55 | self._in_values_changed = False |
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56 | 56 | if 'values' in kwargs: |
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57 | 57 | values = kwargs['values'] |
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58 | 58 | # convert list values to an dict of {str(v):v} |
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59 | 59 | if isinstance(values, list): |
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60 | 60 | # preserve list order with an OrderedDict |
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61 | 61 | kwargs['values'] = OrderedDict((unicode_type(v), v) for v in values) |
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62 | 62 | # python3.3 turned on hash randomization by default - this means that sometimes, randomly |
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63 | 63 | # we try to set value before setting values, due to dictionary ordering. To fix this, force |
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64 | 64 | # the setting of self.values right now, before anything else runs |
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65 |
self.values = kwargs |
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66 | kwargs.pop('values') | |
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65 | self.values = kwargs.pop('values') | |
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67 | 66 | DOMWidget.__init__(self, *args, **kwargs) |
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68 | 67 | |
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69 | 68 | def _values_changed(self, name, old, new): |
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70 | 69 | """Handles when the values dict has been changed. |
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71 | 70 | |
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72 | 71 | Setting values implies setting value names from the keys of the dict. |
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73 | 72 | """ |
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74 | 73 | self._in_values_changed = True |
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75 | 74 | try: |
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76 | 75 | self.value_names = list(new.keys()) |
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77 | 76 | finally: |
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78 | 77 | self._in_values_changed = False |
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79 | 78 | |
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80 | 79 | # ensure that the chosen value is one of the choices |
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81 | 80 | if self.value not in new.values(): |
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82 | 81 | self.value = next(iter(new.values())) |
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83 | 82 | |
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84 | 83 | def _value_names_changed(self, name, old, new): |
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85 | 84 | if not self._in_values_changed: |
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86 | 85 | raise TraitError("value_names is a read-only proxy to values.keys(). Use the values dict instead.") |
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87 | 86 | |
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88 | 87 | def _value_changed(self, name, old, new): |
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89 | 88 | """Called when value has been changed""" |
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90 | 89 | if self.value_lock.acquire(False): |
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91 | 90 | try: |
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92 | 91 | # Reverse dictionary lookup for the value name |
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93 | 92 | for k,v in self.values.items(): |
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94 | 93 | if new == v: |
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95 | 94 | # set the selected value name |
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96 | 95 | self.value_name = k |
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97 | 96 | return |
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98 | 97 | # undo the change, and raise KeyError |
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99 | 98 | self.value = old |
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100 | 99 | raise KeyError(new) |
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101 | 100 | finally: |
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102 | 101 | self.value_lock.release() |
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103 | 102 | |
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104 | 103 | def _value_name_changed(self, name, old, new): |
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105 | 104 | """Called when the value name has been changed (typically by the frontend).""" |
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106 | 105 | if self.value_lock.acquire(False): |
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107 | 106 | try: |
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108 | 107 | self.value = self.values[new] |
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109 | 108 | finally: |
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110 | 109 | self.value_lock.release() |
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111 | 110 | |
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112 | 111 | |
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113 | 112 | class ToggleButtonsWidget(_SelectionWidget): |
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114 | 113 | _view_name = Unicode('ToggleButtonsView', sync=True) |
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115 | 114 | |
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116 | 115 | |
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117 | 116 | class DropdownWidget(_SelectionWidget): |
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118 | 117 | _view_name = Unicode('DropdownView', sync=True) |
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119 | 118 | |
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120 | 119 | |
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121 | 120 | class RadioButtonsWidget(_SelectionWidget): |
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122 | 121 | _view_name = Unicode('RadioButtonsView', sync=True) |
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123 | 122 | |
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124 | 123 | |
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125 | 124 | class SelectWidget(_SelectionWidget): |
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126 | 125 | _view_name = Unicode('SelectView', sync=True) |
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